Alcohol consumption remains a leading cause of injury and death around the world, and the development of effective, replicable, and theory-based interventions and prevention programs is one solution for reducing the negative effect of drinking. The development of rigorous methodologies for testing new theories and for evaluating intervention activities is essential for further growth in the alcohol-harm prevention field. There are limits, however, to current and widely used methodologies. Laboratory studies, for example, offer considerable scientific control but typically occur within an ecological vacuum, void of the real-world contexts, factors, and forces that affect risky-drinking decisions. Intervention strategies found to be effective in the lab may not function as well "in the field." Conversely, field studies and applied research methods often lack experimental control, such as random assignment to conditions. The field of prevention research would benefit greatly from the adoption of methodologies that allow scientists to exercise experimental control within the context of real- world, high-risk drinking and drugging environments. This application proposes two studies designed to test the feasibility of a new methodology for studying drinking behavior: a field experiment with objective measures of drinking behavior and an alcohol-dosing study. The proposed methodology has evolved from studies done by the Pacific Institute for Research and Evaluation in creating and using field survey techniques. PUBLIC HEALTH RELEVANCE: Alcohol contributes an estimated 4% to the world's disease burden resulting in almost 2 million deaths per year. Developing and identifying effective interventions and prevention programs is one approach to reducing alcohol-related harm. This application describes a new research methodology designed to grant prevention researchers both rigorous experiment control and high-ecological validity. If found to be feasible, this method could promote the development of new strategies for reducing alcohol-related harm.